Process for breaking petroleum emulsions



Patented July 1, 1952 No Drawing. Application March 5, 1951,

Serial No. 214,007

This invention relates to petroleum emulsions of the water-in-oil typethat are commonly referred to as cut oil, roily oil, emulsified oil,etc., and which comprises fine droplets of naturally-occurring waters orbrines dispersed in a more or less permanent'state throughout the oilwhich constitutes the continuous phase of the emulsion. I

One object of my invention is to provide a novel process for breaking orresolving emulsions of the kind referred to. I p

Another object of my inventionis to provide an economical and rapidprocess for separating emulsions which have been prepared undercontrolled conditions from mineral oil, such as crude oil and relativelysoft waters or weak brines. Controlled emulsification and subsequentdemulsification under the conditions just mentioned, are of significantvalue in removing impurities particularly inorganic salts from pipelineoil.

Demulsification as contemplated in the present application includes thepreventive step of commingling the demulsifier with the aqueouscomponent which would or might subsequently become either phase of theemulsion, in absence of such precautionary measure. Similarly, suchdemulsifier may be mixed with the hydrocarbon component. 7

The demulsifying agent employed in the present process is a fractionalester obtained "from a polycarboxy acid and a diol obtained by theoxypropylation of a dihydroxy ether of glycerol. This glycerol ether isobtained by reacting one mole of cyclohexanol with one mole of glycid,or any comparable procedurejwhich produces the same compound orequivalent isomer thereof.

Cyclohexanol is obtained by the hydrogenation of phenol and is availablein the open market. My preference is to treat the glycerol ether ofcyclohexanol with sufiicient propylene oxide so that the resultingproduct is not completely water-soluble, i. e., is at least emulsifiableor insoluble in water, and also so the product is'no longer completelyinsoluble in kerosene, i. e., tends to disperse or is soluble inkerosene. Needless to say, the upper molecular weight subsequentlydescribed involves products which are completely water-insoluble andcompletely kerosene-soluble as dififerentiated from dispersibility oremulsifiability. It is to be noted that the original alcohol itself, 1.e., cyclohexanol, is water-soluble, for instance, approximately 3.6partsin 100 partsof water at 20 C., and the dihydroxy compound obtainedby reaction with glycerol moriochloro- 9 Claims. (01.252442) hydrin orglycide iseven more water-soluble and decidedly less kerosene-solublethan cyclohexanol itself! In the hereto appended claimsreference to theproduct being water-insoluble means lack of solubility either by beingonly dispersible, emulsifi able, or rapidly settling out in layers, orfor that matter completely insoluble in the usual sense. The intentionis to differentiate from an ordinary soluble substance. Similarlyreference in. the claims to being at least kerosene-dispersible meansthat the product will at least disperse or emulsify in kerosene or maybe completely soluble in kerosene to give a clear, transparent,.homogeneous solution.'

As stated, the monohydric alcohol has the following structure:

in which The glycide derivative is of the following structure:

Itis this latter compound'which is subjected to oxypropylation. If forconvenience the latter compound is indicated thus: I-IOR/O-H the product obtained by oxypropylation may be indicated thus:

H(OC3H6)1LOR'O(C3H60)7L'H with the proviso that n and n represent wholenumbers which added together equal a sum varying from 15 to 80, and theacidic ester obtained by reaction of the polycarboxy acid may beindicated thus:

in which the characters have their previous significance, andn isa wholenumber not over '2 and R is the radical of the polycarboxy radical ooon"R I w olzon and preferably free from any radicals having more than 8uninterrupted carbon atoms in a single group, and with the furtherproviso that emulsions of the water-in-oil type characterized bysubjecting the emulsion to the action of anesterification product of adicarboxylic acid and a polyalkylene glycol in which the ratio ofequivalents of polybasic acid to equivalents of polyalkylene glycol isin the range of 0.5 to 2.0, in which the alkylene group has from 2 to 3carbon atoms, and in which the molecular weight of the product isbetween 1,500 to 4,000.

Similarly, there have been used esters of .dicarboxy acids andpolypropylene glycols in which 2 moles of the dicarboxy acid ester havebeen reacted with one moleof apolypropylene glycol having'a molecularWeight, for example, of 2,000 so as to form an acidic fractional ester.Subsequent examination of what is said herein in comparison with theprevious example as well as the hereto appended claims will show theline of delineation. between such somewhat comparable compounds. Ofgreater significance, however, is what is said subsequently in regard tothe structure of the parent diol as compared to polypropylene glycolswhose molecular weights may vary from 1,000 to 2,000.

For convenience, what is said hereinafter will be divided into fiveparts:

Part 1 will be concerned with the preparation of the diol by reactingcyclohexanol with glycide or its equivalent;

Part 2 will be concerned with the oxypropylation of the diol obtained inthe manner previously described in Part 1;

Part 3 will be concerned with the preparation of esters from theaforementioned oxypropylation derivatives;

Part 4 will be concerned with the structure of the herein describeddiols and their significance in light of what is said subsequently; and

Part 5 will be concerned with the use of the products herein describedas demulsifiers for breaking water-in oi'l emulsions.

. PART 1 Aspreviouslypointed out the monohydric compound hereinemployed, i. e., cyclohexanol, is available in the open-market.Cyclohexanol is reacted with a suitable reactant, such as glycide,

As far as forming the dihydroxyl compound is concerned other reactionscan be employed which do not involve glycide; for example, one canproduce esters of the kind herein employed by use of a glycerolmonochl'o'r'ohydrin, i. e., either alpha or beta glycerolmonochlorohydrin. Attention is directed'again to the fact that in theprevious formula and in the formulas in the claims it would beimmaterial'whether the free hydroxyl radicals prior to esterificationare present as attached to the first and third terminal carbon atoms, orsecond and third carbon atoms. This is simply an isomeric 'diiferencedepending onhow the epoxy ringis ruptured in the case of glycide, orwhether one employs glycerol alpha monochlorohydrin or glycerol betarncnochlorohydrin. Other suitable procedure involves the use ofepichlorohydrin in a conventional manner. For instance, theoxyprcpy'lated compound can be treated with epichlorohydrin and theresultant product treated with caustic soda so as to reform the epoxyring. The epoxide so obtained can then be treated with water so as toyield a compound having two hydroxyl radicals attached to two of thethree terminall adjacent carbon atoms.

Attention is directed to the fact that the use of glycide requiresextreme caution. This is particularly true on any scale other than smalllaboratory or semi-pilot plant operations. Purely from the standpoint ofsafety in the handling of glycide, attention is directed to thefollowing: (a) If prepared from glycerol monochlorohydrin, this productshould be comparatively pure; (1)) the glycide itself should be as pureas possible as the effect of impurities is difficult to evaluate; (c)the glycide should be introduced carefully and precaution should betaken that it reacts as promptly asintroduced, i. e., that no excess ofglycide isallowed to accumulate; (d) all necessary precaution should betaken that glycide can not'polymerize per se; (6) due to the highboiling point of glycide one can readily employ a typical separatableglass resin 'potas described in U. S. Patent No. 2,499,370, datedMarch'T, 1950-, to De Groote and Keiser, and ofiered for sale bynumerous laboratory supply houses. If such arrangement is used toprepare laboratory-scale duplications, then care should be taken'thatthe heating mantle can be removed rapidly so as to allow for cooling; orbetter still, through an'added opening at the top, the glass resin potor comparable vessel should be equipped with a stainless steel coolingcoil so that the pot can be cooled more rapidly than by mere removal ofmantle. If a stainless steel coil isintroduced it means that theconventional stirrer of the paddle type 'is changed into the centrifugaltype which causes nal heat; and (c) the use of cooling coil so-there isno undue rise in'temperature. All'the foregoing is merely conventionalbut is includeddue to the hazard in handling glycide. 7 1

Examplev 1a The equipment used with a glass resin pot of the kinddescribed above. Into this resin pot were charged 5 gram moles' ofcyclohexanol. This represented 500 grams. To this there were addedslightly over 1% of sodium 'methylate equivalent to 6 grams. Thetemperature of the reaction 'mass was raised to 11'7.5"C. "'5 moles ofglycideequivalent to 370 grams were addedsloW- lyovera period ofapproximately dhours at the 7 rate of about 50 grams per hour. Wh'en thetemperature tended to'rise past '-C.,thereaction :mass was cooled; ifthe temperature showed a tendency to drop below 115or ne -0.,

the reaction mass was heated. *When-allthe glycide had been added thereaction mass {was stirred for approximately one hour longer at 0., andthen was heated to a temperature below the decomposition point ofglycide, for instance, 140 C., andheld at this temperature for anotherhour. Inthisparticular reaction there is less hazard-thanisusually thecase insofar that the amount of glyc ideadded was comparatively-smallandit was'added slowly. Even so, su'choxy-v alkylation should beconducted with extreme-care. Other catalysts can be employed such ascaustic soda; or .caustic potash, but purely as a matter of convenienceI have employed sodium methylate The" amount of catalyst can beincreased but the objection isthat more alkalinematerial must besubsequently removed prior to esterification asdescribed in Part 3,following, or the reaction may 'take place too rapidly or might have itreact with the glycol ether. I

"' "BART2 For a;number'of well known reasons equipment, whetherlaboratory size, semi-pilot. plant size, pilot plant size, or largescale size, is not as a rule designed for a particular alkylene oxide.Invariably and inevitably, however, orparticularly in. the-case oflaboratory equipment and pilot plant size-the design isisuch as to.useany of=the customarilyavailablealkylene oxide, i. e., ethyleneoxide, propylene oxide, butyleneoxide, glycide, epichlorohydrin,-styreneoxide, etc. In the subsequent description of the equipment it becomesobvious that. it is adapted for oxyethylati'on as well asoxypropylation.

Oxypropylations are conducted under a wide variety of conditions, notonly in regard to presence or absence of catalyst, and the kind ofcatalyst, but also inregard'to the'time of reaction, temperature. ofreaction, speed of reaction, pressure during reaction, etc. Forinstance, oxyalklyations can be conducted at temperatures .up toapproximately 200 C. with pressures in about the same range up to about200 pounds per square inch. They can be conducted also at temperaturesapproximatingthe boiling point of water or slightly above, as forexample 95 to 120 C. Under such circumstances the pressure will be lessthan pounds per square inch unless some special'procedure is employed as"is sometimes the case, to wit, keeping an atmosphere of inert gas suchas nitrogen in the. vessel during the reaction.

possibly polymerize the glycide itself rather than .Suchlow-temperature-low reaction rate oxypropylationshave been'describedvery completely iniU. S. Patent No. 2,448,664, to H. R. Fife et al.,

.dated September 7,, 1948.. Low temperature, low

pressure oxypropylations are particularly desirable where the compoundbeing subjected to oxypropylation contains one, two or three points ofcally. The prior figure of seven days applies especially to. large-scaleoperations. I have used conventional equipment with two added auto-.matic features; (a). a solenoid controlled valve which shuts ofi. thepropylene oxide'in event that the temperature gets outside a predeter-'mined and set range, for-instance, 95 to 120 C.,

and (2)) another solenoid valve which shuts off the propylene oxide (orfor that matter ethylene oxide if it is being used) if the pressure getsbeyond a predetermined range, such as 25 to pounds. Otherwise, theequipmentis substan: tially the same as is commonlyie'mployd.for thispurpose where thepressure of reaction. is highenspeed of reaction ishigher, and timeyof reaction'is much shortera In such instancessuchautomatic controls are not necessarily used.

Thus, in preparing the various examples I have found it particularlyadvantageous to .use labora? tory equipment or pilot plant which isdesigned to permit continuous oxyalkylation whether it be oxypropylationor oxyethylation. With= certain obvious changes the equipment can beused also to permit oxyalkylation involving-the use. of glycide' whereno pressure is involved except the vapor pressure of a solvent, if any,which may have been used as a'diluent. .i As'previously pointed out themethod of using propylene oxide is the same as ethylene oxide. Thispoint is emphasized only for the reason that the apparatus is sodesigned and constructed .as to use either oxide. a

The oxypropylation procedure employedin. the preparation of theoxyalkylated derivatives has been uniformly the same, particularly: inlight of the fact that a -continuous' automatically controlled-procedurewas employed In ZitlliS procedure the autoclave was a-conventionalauto-'- clave made of stainless'steel and having-.;a.-ca-'- pacity ofapproximately 15 gallonsand a. work-.- ing pressure of one thousandpounds gaugepressure. This pressure obviously is far beyond, anyrequirement as far as propylene oxidegoes unless there is a reaction ofexplosive violence involved due to accident. The autoclave .was equippedwith the conventional devices and openings, suchas the variable-"speedstirrer operating at-speeds from 50R. P. M. to 500 RP. thermometer welland thermocouple for mechanical thermometer; emptying outlet; pressuregauge, manual'vent line; charge hole for initialreactants; at least oneconnection for introducing the alkylene oxide, such as propylene. oxideor ethylene oxide, to the bottom ofthe' autoclave; along with suitabledevices for 'both'cooling and heating the autoclave, such as a coolingjacket, and, preferably, coils in addition thereto,'with the jacket'soarranged that it is suitable for heating with steam or cooling withwater and further equipped with electrical heating devices. Suchautoclaves are, of course, in essence smallscale replicas of the usualconventional autoclave used in oxyalkylation procedures... In someinstances in exploratory preparations'an auto clave having a smallercapacity, for instance, approximately 3 liters in one case and about 1%gallons inanothercase was used.

Continuous operation, or substantially continuous operation, wasachieved bythe use of a separate containerto hold the alkylene oxidebeing employed, particularly propylene oxide. In conjunction with thesmaller autoclaves, the con,- tainer consists essentially .of'alaboratory. bomb having a capacity of about oneehalf gallon, or somewhatin excess thereof. In some instances a largerbomb was used, to .wit, onehaving a capacity of about one gallon. equipped, also, with an inlet forcharging, and an eductortube going to the bottom of the container so asto permit discharging of alkylene oxide in the liquid phase to theautoclave. A bombhaving a capacity ofabout 60 pounds was used inconnection with the 15-gallon autoclave. Other conventionalequipmentconsists, of course, of the rupture disc, pressure gauge, sightfeed glass, thermometer connection for nitrogen for This bomb waspressuringbomb, etc. The bomb was placedon ascale during use. Theconnections between the bomb'and the autoclave were flexible stainlesssteel hose or. tubing so that, continuous weighings could be madewithout breaking or making any connections. This applies also to thenitrogen line, which was used to pressure the bomb reservoir. To theextent thatit was required, any other usualconventional procedure oraddition. which provided greater safety was used, of course, such assafety glassprotective screens, etc.

Attention is directed againto what has been said :previously in regardto automatic controls whichshut ofi the propylene oxide in eventtemperature of reaction passes out of the predetermined range or ifpressure in the autoclave passes; outof predetermined range.

.With this particular arrangement practically alloxypropylations becomeuniform in that the reaction temperature was held within a few degreesof any selected point, for instance, if. 105 C. was selected as theoperating temperature the maximum point would be at the mostllOf C. or112, C., and the lower point wouldbe95 or possibly 98 C. Similarly, thepressure was .held at approximately 30 pounds within a -poundvariationone way or the other, but might dropto practically zero,especially-where no solvent such as xyleneis employed. The speed ofreaction was comparatively slow under such conditions as compared withoxyalkylations at 200 C. Numerous reactions were conducted in which thetime varied from one day (24 hours) up to three days (72. hours), forcompletion of the final number ofa series. In'some instances thereaction may take-place inconsiderably less time, i. e., 24 hoursor:less,' asfar'as a partial oxypropylation is concerned.

The minimum time recorded was 2 hours. Re-

actions indicated as being complete ,in 2 hours or so may have beencomplete in a lesser period of time in light of the automatic equipmentused. This applies to larger autoclaves where the reactions werecomplete in 5 to hours. In .the addition of propylene oxide, in theautoclave equipment as far as possible the valves were set so-all thepropylene oxide was fed in at a'rate sothe predetermined amount reactedin the first two-thirds ofv the selected period; for instance, if "theselecteclperiod was 3 hours the'rate was set so the-oxide could be fedin in two hours or less. This meant that if the (reaction wasinterruptedautomatically forga period of time for the pressure to.drop,:or thetemperature todrop,

the predetermined amount. of oxide. would .still be added in mostinstances well-within; tlie'predetermined time. period. In one'experimentlthe addition of oxidewas made'over acomparatively longperiod, i. e., 12 hours. In someinstances,

of course, the reaction could be speedednp to quite a marked degree. I

steps must be taken to safeguard against this possibility; if need be asample must bewithdrawn and examined for unreacted propylene oxide. Oneobvious procedure, of course, is to oxypropylate at a modestly highertemperature, for instance, at to C. Unreacted oxide aiTectsdetermination of the acetyl or hydroxyl value'of the hydroxylatedcompound-obtained.

. The higher the molecular weight otthe compound, i. e., towards thelatter stages voi reaction, the longer the time required to add-a givenamount of oxide. One possible explanation is that the molecule, beinglarger, the opportunity for random reaction is decreased. Inversely, thelower the molecular weight'the fasterthe reaction takes place. For thisreason, sometimes at least, increasing the concentration of the catalystdoes not appreciably speed up the .reaction, particularly when theproduct, subjected .to oxyalkylation has a comparatively high'molecularweight. However, as has been pointed out previously, operating at a lowpressure and a low temperature even in large scale operations as much asa week or ten days time may elapse to obtain some of the highermolecular weight derivatives from monohydric or .dihydric materials.

In a numberof operations the counterbalance scale or dial scale holdingthe propylene oxide bomb was so set that when the predetermined amountof propylene oxide had passed into the reaction the scale movement,through a time operating device was set for either one to two hours.This final stirring .period is intended-to avoid the presence orunreacted'oxide.

3 in this sort of operation, of course, the temperaturerange wascontrolled automatically by either use of cooling water, steam, orelectrical heat, so as to raise or lower the temperature. The pressuringof. the propylene oxide into the reaction vessel was also automaticinsofar that the feed stream was set for a slow continuous run which wasshut off in casethe pressure passed a predetermined point as previouslyset out. All the points of design,.construction, etc.,

were conventional including the gases, check valves and entireequipment. .As far as I am aware at least two firms, .and possibl three,

' specialize in auto'cla've equipment such as'Iv have employed inthelaboratory, and are prepared .to

@furnish'equipment of this same' kind. 1 Similarly This point is simplymade as a precaution in the direction-oi safety. Oxyalkylations,particularly involving ethylene oxide, glycide, propylene oxide; etc.,should not be conducted except in equipment specifically designed forthe purpose.

Example 'lb The dihydroxycompound employed was the one previouslydescribed which, for purposes of convenience, will be termed theglycerolether of cyclohexanol. The autoclave employed .was a smallautoclave having a capacity of approximately one gallon. This autoclavewas equipped with various automatic devices. Insome .instances theoxypropylations were run with automatic controls and in other instances,sincethe oxypropylation was very short, with manual controls. Needlessto say, it was immaterial which way the autoclave was handled.

141 grams of the dihydroxylated compound hour. At'the completion of the'reactionpart of .thereacti'on mass was withdrawnand the remainder.subjected to the final oxypropylation step' was described in Example 4b,immediately following- "Emample 4b 140 grams otthe 'reaction 'masspreviously identified as Example 3b and representing the equivalent of}!grams of the original dihyd'roxyldevices adjusted for injecting 665k)1grams of pro- 10 atedmatermly 131' grams of propylene OX1 de an d l Poxlde n about 2 q T e pressm: one gram of catalyst were subjected tofurther mator it maxlmum of {E oxypropylationwith. 43 grams of propyleneoxide. squalte Thls meant that the e The conditions of reaction as faras temperature reaction i take Place and. probably did takfe andpressure were concerned were the same as place at I comparatlvely lowerpressure. Thls in Example 1b, prieceding. Due to the lowconcomperatlvely lower q s was the result 9 centration of catalyst,however, the reaction was the t at least P conslderab le 'very slowsince the oxide was reacted at about lyst w mp The pmpylene oxlde was 10grams per hour? The time required for comadde at t rate of w grams perhour' pletion of the reactionjwitha short stirring period All the oxidewas added in about 1% hours but the'end 17 v m? Was sontinued foranother half hour- In the hereto attachedttablesit Will be noted e... ppthe Selected F'F w that this series shows" theoretical molecular 0".C- Jt d ra y above t bollms P0111J Weights varying from 1,000.10 4,000, andhydroxyl of. a The 1111131911 of oxlde W molecular weights varying froma little less than n Started until the Peatmg devlces had ralsed 900 toa little less than 1.600; In another series the temperature O W1 1en ofexperiments I proceeded furtheiibyithree addithe reaction was complete Pof the macho ti-onal steps; at a molecular weight. corresponding masswas withdrawn as a Sa p e d m to 5,000 theoretical the hydroxylmolecular weight maindersubjected to further oxypropylation as wasapproximately 6000 theoretic-a1 descr e n x e 2 immediatelyfOlIOWlngmolecular weight the hydroxylmolecular weight E 1 Z 2bwasabo-ut 2500, and at,-!7-,000theoreticalmolecular I "camp 6 weight thehydroxyl molecular weight was 2650. 386 grams of the reaction massrepresenting I have esterified. these particular o-xypro'pylated 67;grams of the original dihydroxylated comderivatives as-well as. theonesspecifically depound, 312 grams of propyleneoxide, and'lgrams 35 scribedherein. v I v of caustic soda, were subjected to further reaction Whathas been said; herein is. presented in with 376g'r'a r'ns. of propyleneoxide without adding tabular form in Table 1. immediately following, anymore catalyst. The conditions of reaction, as with some addedinformation asto molecular far-as temperatureand pressure wereconcerned, Weight and as to solubilityof the reactionprodwere'identicallythe same as in Example 117, pre- 0 uct in water,xylene and kerosene.

' A I T TABLE 1 1 Composition Before doniposition at End I I l p M.w. MMax. j y 'byHyd; t Pres.- Time H. 0. Oxide Gata- Theo. H. 0. Ox1de Oata-De ter 0G lbs Hrs.

' Amt Amt. lyst M01. Amt. Amt. lyst m1n.- sq. 1n. grs. grs. grs Wt. grs.grs. grs.

0 lb 141 14 1,000 141 1669 14 v 860" 110 35 2 2b 67 312 7 1,960 67 .6887 1, 294 110 35 2 3b 310 3 2, 935 30 477 3 1,470 110 3 4b s 131 1 3,955a .174 1 v 1, 53c; 11c 35 5% 1 The hydroxylated compound is the glycerolether of cyclohexanol.

cedingl-l The time required to add the oxide was 55 Example 1b wasemulsiiiable in water, soluble the same. The rate of addition wasslightly over 200 grams per hour. At the completion of this stage-bfoxypropylation part of the sample was withdrawn and theremaindersubjected to further oxypropylation as described in Example312, immediately following.

Example 3b 343 grams of the reaction mass identified as Example 2bjpr'eceding,re-presenting 30 grams of the original 'dihy'droxylatedmaterial, 310 grams of propylene oxide, and 3 grams of catalyst, weresubje cte'dfto further oxypropylation by the addi-v tion of 167 grams ofpropylene oxide. The-conditions of reaction as far astemperature andpressure were concerned were substantially the same as in Example 1a,preceding. The t1me required to add the oxide was 3 hours. Due to alower'conc'eritrationoi catalyst the addition rate wa 's considerablyslower, to wit, l5: grams p in xylene and insoluble in kerosene.Examples 2b, 3b and 4b were all insoluble in water, soluble in xylene,and soluble in kerosene,

The final product, i. e.,, at the end of the oxypropylation step, was asomewhat viscous ambercolored fluid which was water-insoluble. This ischaracteristic of all various end products obtained in this series.-These products were,'o-f course, slightly alkalinedue to theresidual-caustic sod-a. employed. This would also be thecaseif sodiummethylate wereused'as acatalyst. 1 I

Speakingor insolubility in water-or. solubility in f kerosenesuchsolubility test can. be made simply by shaking. small amounts of thematerials in a test tube. with water for instance, using 1%,to 5%approximately based onthe amount of water present;

Needlessqto say, the're;is no complete conversion of propyleneioxideintothe desired hydrox-,

ylated compounds. -,.Thisis indicated bythe fact 'a'cetyl or hydroxyl'value.

that the theoretical molecular weight. based onia statistical average'isgreater than the'molecula'r weight calculated by usual methods on' basisof Actually, there' is no completely satisfactory method for determiningmolecular weights of these types of compounds with a high degree ofaccuracy when themolecular weights exceed 2,000. In some instances theacetyl'value or hydroxylvalue, serves as satisfactorily as an indextothe? molecular weight as any other procedure; subject to theabovelimitations, and especiallyin the higher molecular weight range. Ifany difficulty is encountered in the manufacture. of the esters, asdescribed in Part 3 the'stoichiometrical amount of acid or acid.compound should be taken which corresponds to the indicated acetyl orhydroxyl value. This. matter has been discussed in the literature and isa matter of common knowledge and requires no further elaboration. Infact, it is illus-- trated by someof the examples appearing in thepatent previously mentioned.

PART 3 As previously pointed out the present invention is concerned withacidic esters obtained from are not decomposed during-esterification.They (fractional esters) from polycarboxy acids and glycols or otherhydroxylated compounds is well known. Needless to say, various compoundsmay be used such as the low molal ester, the anhydride, the acylchloride, etc. 'However, for purpose of economy it is customary to useeither the acid or the anhydride. A conventional procedure is employed.On a'laboratory scale one can employ a resin pot of the kind describedin U. S. Patent No. 2,499,370, dated March '7; 1950, to De Groote andKeiser, and particularly with one more opening to permit the use of aporous spreaderif'hydrochloric acid gas is to be used as a'catalyst."Such device or absorption spreader consists of minute -Alundumthimble's" which are connected to a glass tube. One can add asulfonic'acid such as para-toluene sulfonic acid as a catalyst. Thereissomeobjection tothis'be cause in some instancesthereis some evidencethat this acid catalyst tends to decompose or rearrange heatoxypropylated compounds, and particularly likely to do self theesterificationtemperature is too high: :In the case of polycarboxy acidssuch as diglycollic' acid, which is strongly acidic there isno needtoadd any catalyst. The

use of hydrochloric gas has one advantage over paratoluene sulfonic acidand that isthat at the endof thereaction it can be removed by flushingout with nitrogen, Whereas 'thereis no I reasonably convenient meansavailable of removingthe paratoluenesulfonic acid or .otherfsulfonicacid employed. If hydrochloric .acid is employedone need only pass thegas through at an exceedingly slow rate so as to keepethe reactionmassacidic. Only a'trace of acid need be .present., .1; have employedhydrochloric. acid gas or:the: aqueous acid itself to eliminate theinitial basic material. My preference, however, is to ,usernozcatalystwhatsoever and to insure complete .dryness'of: the diol as describedin.thezfinal procedure .just preceding of Table 2.., r

The products obtained-inPaItZ preceding may contain ga basiccatalyste Asa general procedure I have, added an amount of halfeconcentratedhydrochloric, acid considerably. in :excess 0f; what .is required toneutralize the -re.sidual catalyst. The. mixture" is shakenthoroughly-and allowed to stand: overnight. It is-then filteredandQrefluxed with the xylene present -untilthe water can be separated inaphase-separating trap.

soon as the product is. substantially free from water the;distillationstops. This preliminary step can be carried out in the flaskto be used .for esterification.- If there is'any furtherv deposition ofsodium chloride during the reflux stage needless to' say a secondfiltrationmay be required. In any-event the neutralor'slightly acidicsolution of the oxypropylated derivatives described in Part 2 is thendiluted further with sufiicient xylene, decalin, petroleum solvent, orthe like, so thatone has obtained approximately a solution. Tothissolution there is added a polycarboxylated,reactantv as previouslydescribed, suchas phthalic anhydride, succinic acidporanhydride,,diglycollic acid, etc. The mixture is refiuxed untilesterification is completeas indicated by elimination of water or, dropin carboxylvalue; Needless to say, if'one produces ahalf-ester from ananhydride such as phthalic anhydride, no water is. eliminated. However,if it is obtained from diglycollic acid, for example,water iseliminated. All such procedures are conventional and have beenso-thoroughly described in the literature that-further considerationwill be limited to a few examples and a comprehensive table.

Other procedures 'for eliminating the basic residual catalyst,,i1" any,can be employed. For example, the oxyalkylation can be conducted inabsence of a solvent or the solvent removed after oxypropylation. Suchoxypropylation end product can then be'acidified with just enoughconcentrated hydrochloric acid to just neutralize the residual basiccatalyst. To this product one can then. add a'small amount ofanhydrous'sodium sulfate (sufficient in quantity to take up; any waterthat is present) and then subject the mass to centrifugal force'so as toeliminate the sodium sulfate and probably the SOdillIILChlOlidC formed.The clear somewhat viscous straw-colored amber liquid soobtained maycontain a small amount of sodium sulfate or. sodium chloride, but, inany event; is perfectly acceptable .for

esterificationin the mannerdescribed:

Itis 'tobe pointed outthat the products here described are not.polyesters in, the sense that there is a plurality-of both diolradioalsandacid radicals; the product is characterized by :having only one diolradical;

trace of water still comes throughand that this mere trace of watercertainly? interieres with .the

acetyl or hydroxyl value determination, at least when a number ofconventional procedures are used and may retard esterification,particularly where there is no sulfonic acid or hydrochloric acidpresent as a catalyst. Therefore, I have preferred to use the followingprocedure; I have employed about 200 grams ofthe diol as described inPart 2; preceding; I have added about 60 grams of benzene, and thenrefluxed this mixture in the glass resin pot being a phase-separatingtrap until the benzene carried out all the water present as water ofsolution or the equivalent. Ordinarily this refluxing temperature is aptto be in the neighborhood of 130 to possibly 150 C. When all this wateror moisture has been removed I also withdraw approximately grams or alittle less benzene and then add the required amount of the carboxyreactant and also about 150 grams of a high boiling aromatic' petroleumsolvent. These I solvents are sold by various oil refineries and, as faras solvent eflect act as if they were almost completely aromatic incharacter. Typical distillation data in I the particular type I haveemployed and main. If the solvent is to be removed by distillation, andparticularly vacuum distillation, then the high boiling aromaticpetroleum solvent might well be replaced by some more expensive solvent,such as decalin or an alkylated decalin whichhas a rather definite orclose range boiling point. The removal of the solvent-of course, ispurely a conventional procedure and requires no elaboration.

In the appended table Solvent #7-3, which appears'in numerous instances,is a mixture of 7'vo1umes of the aromatic petroleum solvent previouslydescribed and 3 volumes of benzene. Reference to Solvent #7- means theparticular petroleum solvent previously described in detail. This wasused, or a similar mixture, in the manner previously described. A largenumber ofthe examples indicated employing decalin were repeated usingthis mixture and particularly with the'preliminary stepof removing allthe water; If one does not intend to remove the solvent my preference isto use the petroleum solvent-ben- 'zenemixture although obviously any ofthe other mixtures, such as decalin and xylene, can be emfound verysatisfactory is the following: played. 5 v I. B. P., 142C. ml., 242 C.The data included in the subsequent tables, i.,e.. 5 ml., 200 C. ml.,244 C. Tables 2 and 3, are self-explanatory, and very 10 ml., 209 C.ml., 248? 0. complete and it is believed no further elaboration 15 ml.,215 C. ml., 252 C.' is necessary:

: 'AIAIBLE 2 v 4mm: EX N0 of E1 1. No. Theo gff- "4 111211 11 /101. dWt.Alrintaof Polyo y- Y V yase on carbox droxy fi 69 22 droxyl Actual Cnpd. Polycarboxy React Gmpd. H: C Value H. V. (grs.) ant lb 1,000 112 131800 214 DiglycolicAnhyd 50.7 20 1,900 57.3 86.6 1,294 205 do 42.4 30 2,935 38. 2 70. 3 1, 470 37. 3 45 3. 055 2a. 4 73. 5 1, 530 33. s 10 1.000I 112 131 300 214 Maleic Anhydri 41.5 10 1, 000 112 131 300 214 PhthalicAnhyd 32. 0 10- 1.000 5 112 p 131 300 214 Snccinic Anhyd 42.3 217 1, 96057. 3 80. 6 l, 294 205 Maleic Anhydrlde. 31 v 20 1, 900 57. 3 s0. 6 1,294 205 Phthalic Anhydride.-. 40. s 2'). 1,960. 57.3 86.6 1,294 205Succinic Anhydride", 31.7 30 2. 035 33.2 70.3 1,470 2 0 M0191 Anhydride.27. 5 3b 2, 035 38.2- 73.3. 1 1,470 200 Phthalic Anhydride-.. 41.0 30 2,935v 33. 2 73. 3 1, 470 205 Succinic Anhydrlde.-. 23.1 40 3. 95s 23. 473. 5 1, 530 103 Maleic Anhydride 24. 7 .40 3, 955 23. 4= 73.5 1,530 103Phthalic Anhydride--. 37.4 40 3. 955 23. 4 73. 5 1, 530 103 SuccinicAnhydride". 25. 2

20 ml" 216 C 111., 5 1 Time of 5 Amt. Esterifl- Water 25ml" Ci 'gg g giSolvent Solvent cation gg Out 301 11., 225 30 ml.-, 264 0. (grs) Temp."0- 1115.) 35 ml., 230 C ml., 270 C. 40 ml., 234 C. ml., 280 C. fig-g522 1 142 2g 0 7 0 145 *3 45 ml., 237 C. ml., 307 229 154 4 After thismaterial is added, refluxingis continfig 3% ued and, of course, is at ahigh temperature, to #7-3 203 3% wit, about to C. If the carboxy re- 3kgactant is an anhydride needless to say no water #7-3 241 140 3 ofreaction appears; if the carboxy reactant is an it; 3% acid, water ofreaction should appear and should #7-3 250 142 3% be eliminated at theabove reaction temperature. 1? fig 3 If it is not'eliminated I simplyseparate out an- A #73 222 142 3 other 10 or 20 cc. of benzene by meansof the 144 M phase-separating trap 'and'thus raise'the temperature to orC.,'-or.ev'en to 200."C.,:'if

need be. My preference is not to go above'200 C. V

tillation and provided there is no objection to a little residue.Actually, when these materials are used for a purpose such asdemulsification the solvent might just as well be allowedtore- Theprocedure formanufacturing the esters has been illustratedby precedingexamples. If for any reason reaction does not take place in a mannerthatis acceptable, attention shouldbe directed to the followingdetails:(a) Recheck the hydroxyl-or acetylrvalue of the'oxypropylated glyceroland use a stoichiometrically equivalent amount of-acid; (b), if thereaction does not proceed with reasonable speed either-,raise thetemperatures indicated orelse extend the period of time up to 12 or 16hours if need' -be; (c) if necessary; use /2% of paratoluene sulfonicacid or:some other acid as a catalyst; (d) if'the esterification doesnot produce a clear product a check shouldbe made to see if an inorganicsalt such asrsodium chloride or sodium sulfate is not'pre cipitatingout. Such salt should be eliminated, at least for explorationexperimentation, and can be removed by filtering. Everything else being'equal as the size of the molecule increases and the reactive hydroxylradical represents a smaller fraction of the entire molecule and thusmore difficulty is involved in obtaining complete esterification.

' "Even under the most carefully controlled conditions'of oxypropylationinvolving comparatively low temperatures and long time of reaction thereare-formedcertain compounds whose, compositionis still obscure. Suchside reaction products can-contribute a substantial proportion of thefinal cogeneric reaction mixture. Various suggestions have been made asto the nature of these compounds, such as being cyclic polymers ofpropylene oxide, dehydration products with the appearance of a vinylradical, or isomers of propylene oxide or derivatives thereof, 1. e., ofan aldehyde, ketone, or allyl alcohol. In some instances 'an attempt toreact the stoichiometric amount of a polycarboxy acid with theoxypropylated derivative results in an excess of the carboxylatedreactant for the reason that apparently under conditions of reactionless reactive hydroxyl radicals are present than indicated by thehydroxyl value. is simply a residue of the carboxylic reactant which canbe removed by filtration or, if desired, the esterification procedurecan be released using an appropriately reduced ratio of carboxylicreactant.

Even the determination of the hydroxyl value "and conventional procedureleaves much to be desired due' either to the cogeneric materialspreviously referred to, or for that matter, the presence of anyinorganic salts or propylene.

'nated.

The solvent employed, if any, can be removed from the finished ester bydistillation and particularly vacuum distillation. The final products orliquids are generally light straw to light amber in color, and showmoderate viscosity. They can be bleached with bleaching clays, filteringchars, and the like. However, for the purpose of demulsification or thelike color is not a factor and decolorization is not justified.

In the aboveinstances I have permitted the solvents to remain present inthe final reaction mass. In other instances I have followed the sameprocedure using decalin or a mixture of decalin or benzene in the samemanner and ultimately removed all the solvents by vacuum distillation.Appearances of the final products are must the same as the diols beforeesterification and in some instances were somewhat darker in color andhad a reddish cast and perhaps somewhat more viscous. I a t' Previousreference has been made to the fact that diols such aspolypropyleneg'ly'col of approximately 2,000 molecularweightdor example,have been esterifiedwith dicarboxy acids and employed as demulsifyingagents; On first examination the difference b'etween thehereindescribed'prod- Under such circumstances there Obviously thisoxide should be elimiwith a monohydricreactant one cannotfdraw ucts andsuch comparable products appears to berather insignificant. In fact,.thedifference is such that it fails to explain the: fact that compounds ofthe kind herein described may be, andf-requently are, 10%, 15% or 20%better on a quantitative basis than the simpler com.- pound previouslydescribed, and demulsify faster and give cleaner oil in many instances,The

method of making such, comparative tests has been described in 'abooklet entitled Treating Oil. Field Emulsioni used in the VocationalTraining Courses, Petroleum Industry Series, of the American PetroleumInstitute.

The difference, of course, does not reside in the carboxy acid butin thediol. Momentarily an eflort willjbe made to emphasize certain things inregard to the structure of a polypropylene glycol, such as polypropyleneglycol of a 2,000 molecular weight. Propylene glycol has a primaryalcohol radical and a secondary alcohol radical. In this sense thebuilding unit which forms polypropylene glycols' is not symmetrical;Obviously, then, polypropylene glycols can be obtained, at leasttheoretically, in which two secondary alcohol groups are united orasecondary alcohol group is united toa primary alcohol group,etherization being involved, of course, in each instance.

Usually noeffort is made to differentiate between oxypropylation takingplace, for example, at the primary alcohol unit radical or the secondaryalcohol radical. Actually, when such products are obtained, such as ahigh molal polypropylene glycol or the products obtained in the mannerherein described one does not obtain a single derivative such asHO(RO)nH in which n has one and only one value, for instance, 14, 15 or16, or the like. Rather, one obtains a cogeneric mixture of closelyrelated or touching homologues. These materials invariably have highmolecular weights and cannot be separated from one another by any knownprocedure without decomposition. The properties of such mixturerepresent the contribution of the various individual members of themixture. On a statistical basis,- of course, n can be appropriatelyspecified. For practical purposes one need only consider the oxypropylation of a monohydric alcohol because in essence this is substantiallythe mechanism involved. Even in such instanceswhere one is concerned asingle formula and say that by following such procedure one can readilyobtain or or of such compound. However, in the case of at leastmonohydric initial reactants one can readily draw the formulas of alarge number of compounds which appear in some of the prob- .ablemixtures or can be prepared as components and mixtures which aremanufactured conventionally. i

: Simply by way of illustration reference is made to the copendingapplication of De Groote, Wir-- tel, and qPettingill, .Serial No.109,791, filed August 11,1949, now Patent No.2,549A34;Howeverymomentarily referring again to a monohydric initial reactant itis obvious-that if one selects any such simple hydroxylated com poundand' subjects such compound to oxyalkylation, such as "oxyethylation';or oxypropyla tion, it becomes obvious thatfone is 're'allypro ducing'atp'olyme'r of the alkylene'oxides except forthe terminal group. 'This'is particularly i7 50 units. If such compound is subjected. tooxyethylation so as to introduce 30 units of ethylene oxide, it is wellknown that one does not obtain a single constituent which, for the sakeof convenience, may be indicated as Instead, one obtains a cogenericmixture of closely related homologues, in which the formula may be shownas the following,

wherein n, as far as the statistical average goes, is 30, but theindividual members present in significant amount may vary from instanceswhere n has a value of 25, and perhaps less, to a point where n mayrepresent 35 or more. Such mixture is, as stated, a cogeneric closelyrelated series of touching homologous compounds. Considerableinvestigation has been made in regard to the distribution curves forlinear polymers. Attention is directed to the article entitledFundamental Principles of Condensation Polymerization, by Flory, whichappeared in Chemical Reviews, volume 39, No. 1, page 137.

Unfortunately, as has been pointed out by Flory and other investigators,there is no satisfactory method, based on either experimental ormathematical examination, of indicating the exact proportion of thevarious members of touching homologous series which appear in cogenericcondensation products of the kind described. This means that from thepractical standpoint, i. e., the ability to describe how to make theproduct under consideration and how to repeat such production time aftertime without diificulty, it is necessary to resort to some other methodof description, or else consider the value of n, in formulas such asthose which have appeared previously and which appear in the claims, asrepresenting both individual constituents in which n has a singledefinite value, and also with the understanding that n represents theaverage statistical value based on the assumption of completeness ofreaction.

This may be illustrated as follows: Assume that in any particularexample the molal ratio of the propylene oxide to the diol is 15 to 1.Actually, one obtains products in which n probably varies from 10 to 20,perhaps even further. The average value, however, is 15, assuming, aspreviously stated, that the reaction is complete. The product describedby the formula is best described also in terms of method of manufacture.

However, in the instant situation it becomes obvious that if an ordinaryhigh molal propyleneglycol is compared to strings of white beads ofvarious lengths, the diols herein employed as intermediates arecharacterized by the presence of a black bead, i. e., a radical whichcorresponds to the glycerol ether of cyclohexanol as previouslydescribed, i. e., the radical Furthermore, it becomes obvious now thatone has a nonsymmetrical radical in the majority of cases for reasonthat in the cogeneric mixture going back to the original formula .uctswhere either 11. or n is zero.

n and n are usually not equal. For instance, if one introduces 15 molesof propylene oxide, n and n could not be equal, insofar that the nearestapproach to equality is where the value of n is 7 and n is 8. However,even in the case of an even number such as 20, 30, 40 or 50, it is alsoobvious that n and n will not be equal in light of what has been saidpreviously. Both sides of the molecule are not going to grow with equalrapidity, i. e., to the same size. Thus the diol herein employed isdifferentiated from polypropylene diol 2000, for example, in that (a) itcarries a heterogeneous unit, i. e., a unit other than a propyleneglycol or propylene oxide unit, (11) such unit is off center, and (c)the effect of that unit, of course, must have some effect in the rangewith which the linear molecules can be drawn together by hydrogenbinding or van der Waals forces, or whatever else may be involved.

What has been said previously can be emphasized in the following manner.It has been pointed out previously that in the last formula immediatelypreceding, 11. or'n' could be zero. Under the conditions of manufactureas described in Part 2 it is extremely unlikely that n is ever zero.However, such compounds can be prepared readily with comparativelylittle difficulty by resorting to a blocking efiect or reaction. Forinstance, if the diol is esterified with alow molal acid such as aceticacid mole for mole and such product subjected to oxyalkylation using acatalyst, such as sodium methylate and guarding against the presence ofany water, it becomes evident that all the propylene oxide introduced,for instance 15 to molecule per polyhydric alcohol necessarily mustenter at one side only. If such product is then saponified so as todecompose the acetic acid ester and then acidified so as to liberate theWater-soluble acetic acid and the water-insoluble diol a separation canbe made and such diol then subjected to esterification as described inPart 3, preceding. Such esters, of course, actually represent prod- Alsointermediate procedures can be employed, i. e., following the sameesteriflcation step afterpartial voxypropylation. For instance, onemight oxypropylate with one-half the ultimate amount of propylene oxideto be used and then stop the reaction. One could then convert thispartial oxypropylated intermediate into an ester by reaction of one moleof acetic acid with one mole of .the herein described diols employed asintermediates and high molal polypropylene glycol, such as polypropyleneglycol 2000.

The most significant fact in this connection is .therfollowing. Theclaims hereto attached are directed to a very specific compound, i. e.,one derived by the oxypropylation of the glycerol ether of cyclohexanol.It is possible that the cyclicstructure present in the glycerol ether ofcyclohexanolis of some significance in determining the'surface-activeproperties of the ultimate derivatives although this is merely specu- 19lation in light of the fact that one. can star with a number of othermonohydric alcohols, some being cyclic and some not. Suchmonohydricalcohols or glycol ethers can then be subjected to treatment withglycide or the like, followed by the same steps previously describedherein. A number of such glycol ethers are available, for example, amongothers, the following: Ethylene glycol monomethyl ether, ethylene glycolethylbutyl ether, ethylene glycol monophenyl ether, ethylene glycolmonobenzyl ether, diethylene glycol monomethyl ether, diethylene glycolmonoethyl ether, and diethylene glycol monobutyl ether.

I have taken each and every one of these glycol ethers and, as a matterof fact, a large number of others, subjected them to reaction withglycide and then oxypropylated the compounds and esterified them in themanner described in the instant application. I have tested all theseproducts for demulsification and at least to date I have not foundanother analogous compound equally effective for demulsification andalso for certain other applications in which surface activity isinvolved. At the moment, based on this knowledge, this particularcompound appears unique for reasons not understood.

PART

Conventional demulsifying agents employed in the treatment of oil fieldemulsions are used as such, or after dilution with any suitablesolvent,such as water, petroleum hydrocarbons, such as benzene, toluene, xylene,tar acid oil, cresol, anthracene oil, etc. Alcohols, particularlyaliphatic alcohols, such as methyl alcohol, ethyl alcohol, denaturedalcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol,etc., may be employed as diluents. Miscellaneous'solvents such as pineoil, carbon tetrachloride, sulfur dioxide extract obtained. in therefining of petroleum, etc., may be employed as diluents. Similarly, thematerial or materials employed as the demulsifying agent of myprocess'm'ay be admixed with one or more of the solvents customarilyused in connection with conventional demulsifying agents. Moreover, saidmaterial or'materials may be used alone or in admixture withothersuitable well-known classes of demulsifying agents. r 7

It is well known that conventionaldemulsifying agents may be used in awater-soluble form,

or in an oil-soluble form, or in a form exhibiting 1 both oilandwater-solubility. Sometimes they may be used in a form which exhibitsrelatively limited oil-solubility. However, since such reagents arefrequently used in a ratio of lto 10,000 or 1 to 20,000, or 1 to-30,000, or even" 1' to 40,000, or 1 to 50,000 as in desalting' practice,such an apparent insolubility'in "oil and water is notsignificant'because said reagentsundoubtedly have solubility within suchconcentrations. This same fact is true in regard to the material ormaterials employed as the demulsi'fyin'g agent of my process. I I

In practicing my process for resolving petroleum emulsions of thewater-in-oil'ty'pe;'a treating agent or demulsifying agent of the kindabo've described is brought into contact with or caused to act upon theemulsion to be treated,.in any of" the various apparatusnow'generally-i'used'to resolve 'or break rpetroleum emulsions with-"achemical'reagent;thetabove'procedurebeingused J alone or in combinationwith other demulsifying "stance, onewhich will tene nts-0r Iii C "7'procedure, such as'the electrical dehydration process.

One type of procedure is to accumulate a volume of emulsified oil in atank and conduct a batch treatment type of demulsification procedure torecover clean oil. 'In this procedure the emulsion is admixed with thedemulsifier, for example by agitating thetank of emulsion and slowlydripping demulsifier into the-emulsion, In some cases mixing is achievedby heating the emulsion while dripping in the demulsifier, dependingupon. the convection currentin the emulsion to produce satisfactoryadmixture; In a third modification of thistype of treatment, acirculating pump withdraws. emulsions .from; e; g, the bottom of thetank, and reintroduces itinto the top of the tank, the demulsifier beingadded, for example, at the. suction side of said circulating pump;

Ina second type of treating procedure;,-the demulsifier is introducedinto the well fluids-at the well-head or at some point'betweenthewellhead and the final oil'storage tank, by means of anadjustableproportioning mechanism or proportioning pump. Ordinarily thefiowof'fluids through the subsequent linesand fittingsssufil'ces toproduce the desired degree of mixing-ordemulsifier and emulsion,although. in -somewinstances additional mixing devices-maybe: introducedinto the flow system. In this general procedure, the system mayincludevarious mechanical devices for withdrawing free; water,separating entrained water, or accomplishing quiescent settling of thechemicalized emulsion. Heating devices may likewise Ice-incorporatedinany of the treating procedures described herein. A third type ofapplication (down-the-hole) -of demulsifier to emulsion is-tointroduce-thedemulsifier either periodically or continuously in dilutedor undiluted form into the Welland-to allow it to come'to the'surfacewith the wellfluids, and then to flow the chemicalized emulsion throughany desirable surface equipmenlg-such-as employed in the other treatingprocedures. particular type of application is decidedly-useful when thedemulsifier is used in connection with acidification of calcareousoil-bearing. strata, especially ifsuspended or dissolved in the--"acidemployed for acidification.

going description, the broad process consists-simply in introducing arelatively smallproportion of demulsifier into a relatively largeproportion of emulsion, admixing the chemicaland'emul sion eitherthrough natural flow or throughspecial apparatus, with or without theapplicationof heat, and allowing the mixture to standquiescentuntil theundesirable Water content of the emulsion separates and settles from themass. I

The following is a typical installation. V A reservoir to hold'thedemulsifier of thekind described (diluted or undilutedl'is placed at-thewell-head Where the efiluent liquids leave the-well. This reservoir orcontainer, which may vary from 5 gallons to 50 gallons for convenience,is connected to a proportioning pump which injects the demulsifierdrop-wise intothe' fluids leaving the well. Such chemicalized fluidspass through the flowli'ne' into a settlingtank; The settling an;

consists "of a tank Gran-y convenientsizeff nduced in 4 to24-hOursr5OO-barre1S toaooo barrels capacity), and in which there is aperpendicular conduit from thetop of the tank to almost the very bottomso as to permit the incoming fluids to pass from the top of the settlingtank to the bottom, so that such incoming fluids do not disturbstratification which takes place during the course of demulsification.The settling tank has two outlets, one being below the water level todrain of? the water resultingirom. demulsification or accompanying theemulsion-as free water,-the other being an oil outlet at the top topermit the passage of dehydrated oil to a second tank, being a storagetank, which holds pipeline or dehydrated oil. If desired, the conduit orpipe which serves to carry the fluids from the well to the settling tankmay include a section of pipe with baiiles to serve as a mixer, toinsure thorough distribution of the demulsifier throughout the fluids,or a heater for raising the temperature of the fluids to some convenienttemperature, for instance, 120 to 160 F., or both heater and mixer.

Demulsification procedure is started by simply setting the pump so as tofeed a comparatively large ratio of demulsifier, for instance, 1:5,000.As soon as a complete break or satisfactory demulsification is obtained,the pump is regulated until experience shows that the amount ofdemulsifier being added is just sufiicient to produce clean ordehydrated oil. The amount being fed at such stage is usually 1 10,000,1 15,000, 1 :20,000, or the like.

In many instances the oxyalkylated products herein specified asdemulsifiers can be conveniently used without dilution. However, aspreviously noted, they may be diluted as desired with any suitablesolvent. For instance, by mixing '75 parts by weight of an oxyalkylatedderivative, for example, the product of Example 30 with 15 parts byweight of xylene and 10 parts by Weight of iso= propyl alcohol, anexcellent demulsifier is obtained. Selection of the solvent will vary,depending upon the solubility characteristics of the oxyalkylatedproduct, and of course will be dictated in part by economicconsiderations, 1. e., cost.

As noted above, the products herein described may be used not only indiluted form, but also may be used admixed with some other chemicaldemulsifier. A mixture which illustrates such combination is thefollowing:

Oxyalkylated derivative, for example, the product of Example 30, 20

A cyclohexylamine salt of a polypropylated naphthalene mono-sulfonicacid, 24%

An ammonium salt of a polypropylated naphthalene mono-sulionio acid,24%;

A sodium salt of oil-soluble mahogany petroleum sulfonic acid, 12

A high-boiling aromatic 15%;

Isopropyl alcohol,

The above proportions are all weight percents.

Having thus described my invention what I claim as new and desire tosecure by Letters Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjectint he emulsion to the action of a demulsifierincluding hydrophile synthetic products, said hydrophile syntheticproducts being characterized by the following formula petroleum solvent,

in which R is the radical of a glycerol ether of cyclohexanol; n and nare numerals with the proviso that n and n equal a sum varying iron;

22 15 to'80', and n-' is a whole number notover' 2, and R-is theradioalof the polybasic acid w /COOH I ooonln' in which n" has its previoussignificance-and with thefurther proviso that the parent dihydroxylatedcompound prior to esterification be Water-insoluble. I J r 1 2. Aprocess for breaking petroleum emulsions of the Water-in-oiltypecharacterized by subjecting the emulsion to the action of ademulsifier including hydrophile synthetic products; said hydrophilesynthetic products being characterized by the following formula 0HooowRt oosHo),.oR o olmo R o00m,"

in which R 'is the radical of a glycerol ether of cyclohexanol; n and nare numerals with the proviso that n and 12 equal a sum varying from 15to 80, and 'n is a whole number not over 2,

and R is the radical of the polybasic acid.

/0 O OH in which 11." has its previous significance, and with thefurther proviso that the parent dihydroxylated compound prior toes'terification be water-insoluble, and at least kerosene-dispersible.

3. A process for breaking petroleum emulsions of the water-in-oil typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being characterized by'the following formula in which R is theradical of a glycerol ether of cyclohexanol; n and n are numerals withthe proviso that n and 11/ equal a sum varying from 15 to 80, and n" isa whole number not over 2. and R. is the radical of the polybasic acidCOOH in which n has its previous significance; said polycarboxy acidhaving not over 8 carbon atoms; and with the further proviso that theparent dihydroxylated compound prior to esterification beWater-insoluble and at least kerosenedispersible.

4. A process for breaking petroleum emulsions of the water-in-oii typecharacterized by subjecting the emulsion to the action of a demulsifierincluding hydrophile synthetic products; said hydrophile syntheticproducts being characterized by the following formula in which R is theradical of a glycerol ether of cyclohexanol; n and n are numerals withthe proviso that n and n equal a sum varying from 15 to 80, and R is theradical of the dicarboxy acid 0 OOH R cooa 23 said "idicarboxylacid 7having :nofi \over18' ;,c,-rbo n atoms;.and-with the ,ufurther, proviso:that the parent dihydroxylatedvcompound prior to esterification beWater-insoluble and at least kerosenedispersible.

5. The process of claim 4 wherein the dicarzhoxyracii-is phthalic acid.

6. @Theprocess of. claim 4 wherein -the: tdicvarboxy acid is maleicacid.

7. The process of claim 4 whenemmhe dicar- {10 The following references:are of :recgrd in ithe file of :this patent:

UNITED STATES PATENTS Number 2,562,873

1. A PROCESS FOR BREAKING PETROLEUM EMULSIONS OF THE WATER-IN-OIL TYPECHARACTERIZED BY SUBJECTING THE EMULSION TO THE ACTION OF A DEMULSIFIERINCLUDING HYDROPHILE SYNTHETIC PRODUCTS, SAID HYDROPHILE SYNTHETICPRODUCTS BEING CHARACTERIZED BY THE FOLLOWING FORMULA